.Net has a tool called the XML Schema Definition Tool (XSD.EXE) which can turn XSD schemas into classes.  Also, it will try to make it so those classes will conform to the schema when serialized as XML.

http://msdn.microsoft.com/library/default.asp?url=/library/en-us/cptools/html/cpconxmlschemadefinitiontoolxsdexe.asp

xsd.exe pathToXSD.xsd /classes /language:VB /outputdir:C:output

You can then serialize and deserialize the object into/from XML.

http://msdn.microsoft.com/library/default.asp?url=/library/en-us/cpref/html/frlrfSystemXmlSerializationXmlSerializerClassTopic.asp

http://msdn.microsoft.com/library/default.asp?url=/library/en-us/cpref/html/frlrfSystemXmlSerializationXmlSerializerClassDeserializeTopic.asp

It seems like validating an XML document against a schema would be a pretty simple thing to do in the .Net framework, seeing as how they have such deep support for dealing with XML.

But as of yet, I haven’t found a simple way to do it.

Here is the code I have been using to validate XML against an XML Schema.

Imports System.IO
Imports System.Xml
Imports System.Xml.Schema


    Private schemaValidation As New ValidationEventHandler(AddressOf ValidationHandler)

    Private Function ValidateXml(ByVal xmlFileName As String, ByVal xmlSchemaName As String) As Boolean
        Using myFile As New FileStream(xmlFileName, FileMode.Open, FileAccess.Read, FileShare.None)
            Dim xDoc As New Xml.XmlDocument()
            xDoc.Load(myFile)
            xDoc.Schemas.Add(GetSchema(xmlSchemaName))
            Try
                xDoc.Validate(schemaValidation)
                Return True
            Catch ex As XmlSchemaValidationException
                Console.Write(ex.ToString)
                Return False
            Catch ex As XmlSchemaException
                Console.Write(ex.ToString)
                Return False
            Catch ex As Exception
                Console.Write(ex.ToString)
                Return False
            End Try
        End Using
    End Function

    Private Function GetSchema(ByVal filePath As String) As XmlSchema
        Dim schema As XmlSchema
        Using s As New System.IO.FileStream(filePath, FileMode.Open)
            Using reader As New StreamReader(s)
                schema = XmlSchema.Read(reader, Nothing)
            End Using
        End Using
        Return schema
    End Function

    Private Sub ValidationHandler(ByVal sender As Object, ByVal e As System.Xml.Schema.ValidationEventArgs)
        Throw e.Exception
    End Sub